1. Field of the Invention
This invention relates to a liquid crystal display apparatus having a flexible substrate.
2. Description of the Related Art
A liquid crystal display apparatus that consumes minimal power has been used currently as a display unit for portable electronic apparatuses such as portable information terminals or cellular phones. In particular, reflection type liquid crystal apparatuses are used for most products as a backlight is not necessary, resulting in minimal power consumption and increased battery life.
Meanwhile, a liquid crystal display apparatus that employs a resin film substrate instead of a conventional glass substrate has been developed to answer the ever-increasing need for further miniaturization and weight decrease of the electronic apparatus.
One example of a reflection type liquid crystal display apparatus having a film substrate as described hereinabove will be described briefly with reference to FIG. 3. FIG. 3 is a diagram showing a partial cross-sectional view of a liquid crystal display apparatus having a conventional configuration. In FIG. 3, the liquid crystal display apparatus 100 comprises a first film substrate 110 and a second film substrate 120, which face each other, and a liquid crystal layer 130 that is sealed between the two film substrates 110 and 120.
A laminated structure of an electrode layer 115 consisting of transparent conductive film such as ITO (indium-tin oxide) operates liquid crystal molecules of the liquid crystal layer 130 and an orientation film 116 controls the orientation of liquid crystal molecules are formed on the liquid crystal layer side of the first film substrate 110. Another laminated structure of an electrode layer 125 and orientation film 126 are formed on the liquid crystal layer side of the second film substrate 120. Furthermore, a reflection plate 128 is provided on the opposite side of the second film substrate 120 (the outer face side of the second film substrate 120).
Furthermore, a reflector 140 having one surface on which a reflection film 141 of aluminum is formed on the outer face side of the first film substrate 110. An adhesive 142 is formed between the reflection film 141 and the substrate 110 .
The liquid crystal display apparatus 100 having the above-mentioned configuration has been used as a reflection type liquid crystal display apparatus in which solar energy or other external illumination is used as the light source. Light incident from the outside of the second substrate 120 is reflected on the reflection film 141 and used for displaying.
Furthermore, because a film substrate that is thinner than a conventional glass substrate is used as the substrate, it is possible to make an electronic apparatus having the above-mentioned liquid crystal display apparatus thin, and parallax is suppressed to bring about a high quality display.
However, according to the configuration of the liquid crystal display apparatus 100, because the exterior type reflector 140 reflects the incident light, the light incident from the second substrate 120 side to the liquid crystal display apparatus 100 passes through the two substrates 110 and 120 and a reflection plate 128 inevitably before the light reaches the reflection film 141 of the reflector 140. As the result, the light transmission loss is large, and the brightness of the display is insufficient.
Furthermore, because the liquid crystal display apparatus 100 comprising the above-mentioned film substrate is a component used as the display unit of, for example, a cellular phone and low cost is required, it is very important to simplify the configuration and manufacturing process of the liquid crystal display apparatus so that the cost is reduced.
The present invention has been accomplished to solve the above-mentioned problems, and it is an object of the present invention to provide a liquid crystal display apparatus having a flexible substrate that is capable of displaying high quality images with high brightness.
It is another object of the present invention to provide a liquid crystal display apparatus having a simplified configuration that reduces manufacturing costs.
To achieve the above-mentioned object, a liquid crystal display apparatus according to a first aspect of the present invention comprises a pair of substrates disposed to face each other with interposition of a liquid crystal layer, at least one of the substrates is a flexible substrate, and a plurality of concave faces each having a spherical inner surface and formed continuously on the surface of at least one substrate facing the liquid crystal layer.
According to the configuration in accordance with the present invention, because the concave faces are formed continuously on one surface of a flexible substrate, the configuration of the liquid crystal display is simplified to bring about the reduced manufacturing cost.
Next, the liquid crystal display apparatus according to a second aspect has a metal reflection film formed on the substrate surface.
According to the above-mentioned configuration, the reflection type liquid crystal display apparatus of the present invention has a built-in reflection plate for reflecting the light between the pair of substrates. Because the metal reflection film is shaped as described hereinabove, the reflection efficiency of the metal reflection film is improved to bring about a bright display.
Next, the liquid crystal display apparatus according to a third aspect has a depth of the concave faces ranging from 0.1 xcexcm to 3 xcexcm, an inclination distribution of the inner surface of the concave faces ranging from xe2x88x9230 degrees to +30 degrees, and a pitch between adjacent concave faces ranging from 5 xcexcm to 50 xcexcm.
According to the configuration as described hereinabove, because the reflection efficiency of the metal reflection film is optimized, the light incident from the outside is reflected efficiently, and a bright reflection display is realized.
Next, the liquid crystal display apparatus according to a fourth aspect has a metal reflection film having a film thickness ranging from 80 xc3x85 to 300 xc3x85.
According to the configuration as described hereinabove, because the film thickness of the metal reflection film is made very thin, a bright transmission display is realized and the metal reflection film reflects light efficiently even when a light source for transmission display is used that is external to the substrate to fabricate a semi-transmission/reflection type liquid crystal display apparatus. In other words, a semi-transmission/reflection type liquid crystal display apparatus that gives a bright and easily visible display for both transmission display and reflection display is realized.
Next, the liquid crystal display apparatus according to a fifth aspect has a metal reflection film with a film thickness ranging from 80 xc3x85 to 100 xc3x85.
According to the configuration as described hereinabove, a semi-transmission/reflection type liquid crystal display apparatus that gives a bright reflection display and an extraordinarily bright transmission display is realized.
Next, the liquid crystal display apparatus according to a sixth aspect has a color filter formed directly on the metal reflection film.
According to the configuration as described hereinabove, because the color filter is formed on the surface on which light incident from the outside is reflected, the parallax and color deviation is minimized and the high quality display is realized.
Next, the liquid crystal display apparatus according to a seventh aspect has a colored substrate with the surface on which the concave faces are formed.
According to the configuration as described hereinabove, the color of the colored substrate may be used as the display color in the case that a reflection type liquid crystal display apparatus is fabricated. In other words, a display having the color purity higher than that of the display obtained by means of orientation control of liquid crystal molecule is realized.
Next, the liquid crystal display apparatus according to a eighth aspect has a flexible substrate comprising polyallylate base, polycarbonate base, polyethersulphone base, or polyethylene terephthalate base resin.
According to the configuration described hereinabove, because the resins described hereinabove are highly transparent, the bright display is realized for both reflection display and transmission display. Furthermore, because the above-mentioned resin materials are excellent in heat resistance and a film can be formed at a high temperature, a high quality liquid crystal display apparatus is realized.